2012
Autores
Vaz, CB; Camanho, AS;
Publicação
JOURNAL OF THE OPERATIONAL RESEARCH SOCIETY
Abstract
This study develops a framework that combines different management science methods to provide insights concerning the performance of retailing stores. First, the framework enables to specify appropriate targets for stores of a retail network using data envelopment analysis. This involves comparing stores within homogenous groups, that is, supermarkets and hypermarkets. Second, the framework compares the overall performance of these two groups. This requires the combined use of a Malmquist-type index and statistical tests. This index is decomposed into sub-indices for comparing the differences between groups in terms of the efficiency spread in each group of stores and the productivity differences between the best-practice frontiers spanned by the benchmark stores from each group. The hypothesis tests are used to verify if the differences between groups captured by the sub-indices are statistically significant. Journal of the Operational Research Society (2012) 63, 631-645. doi:10.1057/jors.2011.63 Published online 13 July 2011
2009
Autores
Camanho, AS; Portela, MC; Vaz, CB;
Publicação
COMPUTERS & OPERATIONS RESEARCH
Abstract
This paper develops a method based on data envelopment analysis (DEA) for efficiency assessments taking into account the effect of non-discretionary factors. A typology that classifies the non-discretionary factors into two groups is proposed: the factors that characterize the external conditions where the decision making units (DMUs) operate (external factors), and the factors that are internal to the production process but cannot be controlled by the decision makers (internal factors). This paper proposes an enhanced DEA model that accommodates non-discretionary inputs and outputs and treats them differently depending on their classification as internal or external to the production process. This generalized model integrates the previous approaches for dealing with non-discretionary variables described in the DEA literature. The model defines the efficient frontier based exclusively on the discretionary variables and internal non-discretionary factors, but the potential peers of each DMU are restricted to other units facing comparable external conditions (represented by the external non-discretionary factors). The peer selection criteria implemented in the DEA model is informed by decision makers' opinion, The applicability of the model developed is illustrated with a real-world assessment of retailing stores.
2010
Autores
Vaz, CB; Camanho, AS; Guimaraes, RC;
Publicação
ANNALS OF OPERATIONS RESEARCH
Abstract
This paper describes a method for the assessment of retail store performance based on Data Envelopment Analysis (DEA). The assessment considers the stores as complex organizations that aggregate several subunits, corresponding to sections with management autonomy. This structure motivated an analysis at two different levels: the section level and the store level. The performance assessment of the sections envolves a comparison among similar sections located in different stores, and evaluates efficiency spread. This is followed by an analysis at the store level to define targets for the sections. This analysis takes into account the interdependencies of the sections composing a store, as they share limited resources such as the floor area. This is achieved using a Network DEA model, which determines the maximum store sales allowing for reallocations of area among the sections within a store. The method developed is illustrated using a case study consisting of a Portuguese chain of supermarkets.
2023
Autores
Vaz, B; Ferreira, P;
Publicação
Springer Proceedings in Mathematics and Statistics
Abstract
This work aims to assess the performance of European countries on the deployment of low-emission vehicles in road transportation. For this purpose, a model based on Data Envelopment Analysis (DEA) is used to calculate a composite indicator for several European countries, aggregating seven sub-indicators built from a data set for the 2019 year. Various virtual weight restrictions schemes of the sub-indicators are studied to explore the robustness of the performance results. By adopting the most robust scheme, the performance results obtained indicate that most European countries have the potential to improve their practices towards better road transport sustainability, by emulating the best practices observed in the four identified benchmarks. Thus, the inefficient countries should take measures to better support the market share of plug-in electric vehicles. In addition, the railway sector and the penetration of renewable energies should be enhanced to improve road transportation sustainability. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.
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